Surgical stapling instrument incorporating a multi-stroke firing mechanism with a flexible rack

ABSTRACT

A surgical stapling and severing instrument particularly suited to endoscopic procedures incorporates a handle that produces separate closing and firing motions to actuate an end effector. In particular, the handle produces multiple firing strokes in order to reduce the required amount of force required to fire (i.e., staple and sever) the end effector. A flexible rack transmits these firing strokes to a firing rod that reciprocates in an elongate shaft to actuate the end effector. The flexible rack advantageously stows into a pistol grip of the handle when retracted to minimize handle length.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation in part of U.S. patentapplication Ser. No. 11/052,632, “MULTI-STROKE MECHANISM WITH AUTOMATEDEND OF STROKE RETRACTION” to Jeffrey S. Swayze et al., filed Feb. 7,2005, now U.S. Pat No. 7,083,075 which in turn was a continuation inpart of U.S. patent application Ser. No. 10/673,930 filed Sep. 29, 2003entitled “SURGICAL STAPLING INSTRUMENT INCORPORATING A FIRING MECHANISMHAVING A LINKED RACK TRANSMISSION”, to Jeffrey S. Swayze, which issuedas U.S. Pat. No. 6,905,057, the disclosures of both of which are herebyincorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates in general to surgical stapler instrumentsthat are capable of applying lines of staples to tissue while cuttingthe tissue between those staple lines and, more particularly, toimprovements relating to stapler instruments and improvements inprocesses for forming various components of such stapler instrumentsthat accomplish firing with multiple strokes of a trigger.

BACKGROUND OF THE INVENTION

Endoscopic and laparoscopic surgical instruments are often preferredover traditional open surgical devices since a smaller incision tends toreduce the post-operative recovery time and complications. The use oflaparoscopic and endoscopic surgical procedures has been relativelypopular and has provided additional incentive to develop the proceduresfurther. In laparoscopic procedures, surgery is performed in theinterior of the abdomen through a small incision. Similarly, inendoscopic procedures, surgery is performed in any hollow viscus of thebody through narrow endoscopic tubes inserted through small entrancewounds in the skin.

Laparoscopic and endoscopic procedures generally require that thesurgical region be insufflated. Accordingly, any instrumentationinserted into the body must be sealed to ensure that gases do not enteror exit the body through the incision. Moreover, laparoscopic andendoscopic procedures often require the surgeon to act on organs,tissues and/or vessels far removed from the incision. Thus, instrumentsused in such procedures are typically long and narrow while beingfunctionally controllable from a proximal end of the instrument.

Significant development has gone into a range of endoscopic surgicalinstruments that are suitable for precise placement of a distal endeffector at a desired surgical site through a cannula of a trocar. Thesedistal end effectors engage the tissue in a number of ways to achieve adiagnostic or therapeutic effect (e.g., endocutter, grasper, cutter,staplers, clip applier, access device, drug/gene therapy deliverydevice, and energy device using ultrasound, RF, laser, etc.).

Known surgical staplers include an end effector that simultaneouslymakes a longitudinal incision in tissue and applies lines of staples onopposing sides of the incision. The end effector includes a pair ofcooperating jaw members that, if the instrument is intended forendoscopic or laparoscopic applications, are capable of passing througha cannula passageway. One of the jaw members receives a staple cartridgehaving at least two laterally spaced rows of staples. The other jawmember defines an anvil having staple-forming pockets aligned with therows of staples in the cartridge. The instrument includes a plurality ofreciprocating wedges which, when driven distally, pass through openingsin the staple cartridge and engage drivers supporting the staples toeffect the firing of the staples toward the anvil.

An example of a surgical stapler suitable for endoscopic applications isdescribed in U.S. Pat. No. 5,465,895, which advantageously providesdistinct closing and firing actions. Thereby, a clinician is able toclose the jaw members upon tissue to position the tissue prior tofiring. Once the clinician has determined that the jaw members areproperly gripping tissue, the clinician can then fire the surgicalstapler with a single firing stroke, thereby severing and stapling thetissue. The simultaneous severing and stapling avoids complications thatmay arise when performing such actions sequentially with differentsurgical tools that respectively only sever or staple.

Generally, a single closing stroke followed by a single firing stroke isa convenient and efficient way to perform severing and stapling.However, in some instances, it would be desirable for multiple firingstrokes to be required. For example, surgeons are able to select from arange of jaw sizes with a corresponding length of staple cartridge forthe desired length of cut. Longer staple cartridges require a longerfiring stroke. Thus, to effect the firing, a hand-squeezed trigger isrequired to exert a larger force for these longer staple cartridges inorder to sever more tissue and drive more staples, as compared to ashorter staple cartridge. It would be desirable for the amount of forceto be lower, comparable to that needed for shorter cartridges so as notto exceed the hand strength of some surgeons. In addition, some surgeonsnot familiar with the larger staple cartridges may become concerned thatbinding or other malfunction has occurred when an unexpectedly higherforce is required.

In U.S. Pat. No. 6,905,057, a multiple firing stroke handle for anendoscopic surgical stapling and severing instrument succeeds inreducing these firing forces by advancing a firing mechanism during eachsqueeze of the firing trigger, mechanically coupling this firing motionthrough a pawl into a linked rank. In addition to reducing the forcerequired to squeeze the firing trigger, the linked rack stows into apistol grip of the handle and advantageously reduces the length of thehandle as compared to a rigid rack.

Consequently, a significant need exists for a surgical staplinginstrument which has a multiple stroke firing mechanism with a reducedhandle length.

BRIEF SUMMARY OF THE INVENTION

The invention overcomes the above-noted and other deficiencies of theprior art by providing a surgical stapling and severing instrument thatadvantageously incorporates a flexible firing member in a handle. Thehandle guides a distal portion of the flexible firing memberlongitudinally to translate a firing motion into a shaft firing memberthat translates in a shaft to actuate a distally attached end effector.The handle deflects a proximal portion of the flexible firing memberfrom the longitudinal axis during retraction to advantageously reducethe required length of the handle.

These and other objects and advantages of the present invention shall bemade apparent from the accompanying drawings and the descriptionthereof.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention,and, together with the general description of the invention given above,and the detailed description of the embodiments given below, serve toexplain the principles of the present invention.

FIG. 1 is a left isometric view of a surgical stapling and severinginstrument in an initial state with the closure and firing triggerreleased and the end effector (staple lying assembly) open.

FIG. 2 is a right isometric exploded view of the surgical stapling andsevering instrument of FIG. 1 with the staple applying assembly omitted.

FIG. 3 is a right isometric view of a handle of the surgical staplingand severing instrument of FIG. 2 in a clamped and partially fired statewith a right shell of a handle housing and rotation knob removed toexpose a first version of a flexible firing rack consistent with aspectsof the invention.

FIG. 4 is an aft right isometric view of the flexible firing rack andclosure yoke of the surgical stapling and severing instrument of FIG. 2.

FIG. 5 is a front left isometric view of the flexible firing rack ofFIG. 2.

FIG. 6 is an aft right isometric view of the flexible firing rack ofFIG. 2.

FIG. 7 is an aft view in elevation of the flexible firing rack of FIG.2.

FIG. 8 is a front left isometric view of an alternative flexible firingrack with top apertures for the surgical stapling and severinginstrument of FIG. 1.

FIG. 9 is a front left isometric view of another alternative flexiblefiring rack with sprocket holes for manual retraction for the surgicalstapling and severing instrument of FIG. 1.

FIG. 10 is an aft right isometric view of an alternative surgicalstapling and severing instrument with a right handle shell and rotationknob omitted to expose a loop chain drive and a linked rack in aninitial state.

FIG. 11 is a right side view in elevation of the alternative surgicalstapling and severing instrument of FIG. 10 with the right handle shelland rotation knob omitted.

FIG. 12 is an aft right isometric exploded view of the alternativesurgical stapling and severing instrument of FIG. 10 with the stapleapplying assembly omitted.

FIG. 13 is a left side view in elevation of a handle of the alternativesurgical stapling and severing instrument of FIG. 10 with the righthandle shell, main body of the closure yoke assembly, rotation knob,closure tube and closure trigger omitted to expose a closure yokedistally advanced (i.e., closed end effector) and the loop chain driveand linked rack in an initial, unfired state.

FIG. 14 is a left side view in elevation of the portion of the handle ofthe alternative surgical stapling and severing instrument of FIG. 13after the loop chain drive has moved the linked rack to a fired state.

FIG. 15 is an aft left isometric view of the firing trigger, loop chaindrive, linked rack and manual retraction mechanism of the portion of thehandle of FIG. 14.

FIG. 16 is an aft left isometric view of the firing trigger, loop chaindrive, and linked rack of FIG. 15.

FIG. 17 is an aft right isometric exploded isometric view of the loopchain drive of FIG. 16 including a ratchet gear coupling to the firingtrigger.

FIG. 18A is a left side view in elevation taken in vertical andlongitudinal cross section through an alternative flexible threadedcable firing mechanism in an initial unfired state for the surgicalstapling and severing instrument of FIG. 1.

FIG. 18B is a left side view in elevation taken in vertical andlongitudinal cross section through the alternative flexible threadedcable firing mechanism of FIG. 18A in a fully fired state.

FIG. 18C is a left side view in elevation taken in vertical andlongitudinal cross section through the alternative flexible threadedcable firing mechanism of FIG. 18B after automatic firing retraction.

FIG. 18D is a forward view in elevation taken in vertical and transversecross section through the alternative flexible threaded cable firingmechanism of FIG. 18A.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, a surgical stapling and severing instrument 10 includesmulti-stroke firing of an end effector, which in the illustrativeversion is a staple applying apparatus 12. An upper jaw (anvil) 14 maybe repeatably opened and closed about its pivotal attachment to a lowerjaw 15 of an elongate (staple) channel 16 engaged to a replaceablestaple cartridge 17. The staple applying assembly 12 is proximallyattached to elongate shaft 18, forming an implement portion 19. When thestaple applying assembly 12 is closed, the implement portion 19 presentsa small cross-sectional area suitable for insertion through a trocar byan externally connected and manipulated handle 21. In FIG. 2, a flexiblefiring rack 22 incorporated into the handle 21 advantageously transfersfiring motion to the implement portion 19 yet retracts to enable areduced length handle 21.

In FIGS. 1-3, the handle 21 has user controls mounted on its handlehousing 23, such as a rotation knob 24 that rotates the elongate shaft18 and staple applying assembly 12 about a longitudinal axis of theshaft 18. A closure trigger 26, which pivots in front of a pistol grip27 about a closure trigger pin 28 engaged laterally across the handlehousing 23, is depressed to close the staple applying assembly 12. Amultiple stroke firing trigger 30, which pivots in front of the closuretrigger 26, causes the staple applying assembly 12 to simultaneouslysever and staple tissue clamped therein. Since multiple firing strokesare employed to reduce the amount of force required per stroke by thesurgeon's hand, right and left indicator wheels 32, 33 (the formerdepicted in FIG. 3) that turn on an axle 31 (FIG. 3) rotate presentingindicia of the firing progress. For instance, full firing travel mayrequire three full firing strokes and thus the indicator wheels 32, 33rotate up to one-third of a revolution each per stroke. A manual firingrelease lever 34 allows retraction before full firing travel if desiredand allows assistance to retract in the presence of binding or a failurein the retraction bias. The manual firing release lever 34 is normallydownwardly biased by a coil spring 35 (FIG. 3). A closure release button36 is outwardly presented when the closure trigger 26 is clamped andpartial firing has not occurred that would prevent unclamping theclosure trigger 26.

In FIG. 3, the elongate shaft 18 has as its outer structure alongitudinally reciprocating closure tube 38 that pivots the anvil 14 toeffect closure in response to proximal depression of the closure trigger26 of the handle 21. The elongate channel 18 is connected to the handle21 by a frame 40 that is internal to the closure tube 38. The frame 40is rotatably engaged to the handle 21 so that twisting the rotation knob24 causes rotation of the implement portion 19. Each half shell of therotation knob 24 includes an inward projection 41 that enters arespective longer side opening 42 in the closure tube 38 and projectsinward to engage the frame 40 that determines the rotated position ofthe implement portion 19. The longitudinal length of the longer opening42 is sufficiently long to allow longitudinal closure motion of theclosure tube 38.

An upper portion 44 of the closure trigger 26 pushes forward a closureyoke assembly 46 via a closure link 48. The closure link 48 is pivotallyattached at its distal end by a closure yoke pin 50 to the closure yokeassembly 46 and is pivotally attached at its proximal end by a closurelink pin 52. The closure trigger 26 is urged to the open position by aclosure trigger tension spring 54 that is connected proximally to theupper portion 44 of the closure trigger 26 and to the handle housing 23formed by right and left half shells 56, 58. The right and left halfshells 56, 58 each include a closure yoke guide post 59 that slideswithin respective horizontally elongate rectangular apertures 60 formedin each side of the closure yoke assembly 46, with the post 59 at adistal position in the respective aperture 60 when the closure yokeassembly 46 is proximally positioned with the anvil 14 open and at aproximal position in the aperture 60 when the closure yoke assembly 46is distally positioned with the anvil 14 closed.

The upper portion 44 of the closure trigger 26 includes a proximal crest62 with an aft notch 64. The closure release button 36 and a pivotinglocking arm 66 are connected by a central lateral pivot 68. Acompression spring 70 biases the closure release button 36 proximally(clockwise about the central lateral pivot 68 as viewed from the right).With the upper portion 44 back when the closure trigger 26 is released,the pivoting locking arm 66 rides upon the proximal crest 62 drawing inthe closure release button 36. When the closure trigger 26 reaches itsfully depressed position, it should be appreciated that the aft notch 64is presented below the pivoting locking arm 66, which drops into andlocks against the aft notch 64 under the urging of the compressionspring 70. With the firing components retracted, manual depression ofthe closure release button 36 rotates the pivoting locking arm 66upward, unclamping the closure trigger 26.

Once the closure trigger 26 is proximally clamped, a firing rod 72 isdistally moved from the handle 21 in response to the multiple strokefiring trigger 30 being drawn to the pistol grip 27 with the amount offiring travel visible to the surgeon on right and left indicator gaugewheels 32, 33. The firing trigger 30 pivots about a firing trigger pin74 that laterally traverses and is engaged to the right and left halfshells 56, 58.

The flexible firing rack 22 is initially retracted, urged to remain inthis position by a combination tension/compression spring 76 that isconstrained within the pistol grip 27 of the handle 21, with itsnonmoving end 78 connected to the housing 23 and a moving end 80connected to a downwardly flexed and proximal, retracted end 82 of asteel band 84 that may be molded into the flexible firing rack 22 (FIGS.6-7). Alternatively, the steel band 84 may underlie and attach to afront end 85 of the flexible firing rack 22 (FIG. 3). As a furtheralternative, a proximally presented hook 86 on the flexible firing rack22 (FIGS. 4-5) may serve as an attachment for a retraction spring (notshown). In FIGS. 5-6, the front end 85 of the flexible firing rack 22includes a female attachment receptacle 87 that engages a proximal endof the firing rod 72. A toothed rack segment 88 (FIGS. 2-5) is upwardlypresented along a left edge of the flexible firing rack 22.

In FIGS. 4-6, in addition to incorporating a degree of downwardflexibility into the flexible firing rack 22 by choice of material, aplurality of transverse slots 90 passing through a bottom portionaccommodate the tighter radius of turn, enabling downward bending intothe pistol grip 27, thereby minimizing the longitudinal length of thehandle 21. Yet, the flexible firing rack 22 forms a sufficiently rigidrack structure in its upper portion when straightened by distaladvancement into the closure yoke assembly 46 to transfer a significantfiring force through the firing rod 72 in the implement portion 19, yetreadily retracts into the pistol grip 27. It should be appreciated thatthe combination tension/compression spring 76 increases the amount offiring travel available while essentially reducing the minimum length byhalf over a single spring.

In FIG. 3, a distal pinion spur gear 91 engages the toothed rack segment88, turned thereby during firing about a distal gear axle 92 whoselateral ends turn within receptacles in the handle half shells 56, 58. Aproximal dual gear 93 has a left large spur gear 94 that is turned onaxle 31 by the distal pinion spur gear 91. A coaxial right small ratchetgear 95 turns within a hub 96 that is attached to the manual firingrelease lever 34. A clip spring 97 urges a pawl 98 within the hub 96into contact with the ratchet gear 95 so that actuation of the manualfiring release lever 34 back drives the dual gear 93, the pinion spurgear 91, and the flexible firing rack 22 while an unlocking cam surface99 unlocks an anti-backup mechanism 100.

With particular reference to FIGS. 2-3, the anti-backup mechanism 100prevents the combination tension/compression spring 76 from retractingthe flexible firing rack 22 between firing strokes. A coupling slidetube 101 has a proximally open cylindrical cavity 102 shaped to receivethe front end 85 of the flexible firing rack 22 with a narrower distalopening 103 that allows passage of the firing rod 72 to communicate thefiring motion. A pair of lateral recesses 104 proximally placed on thecoupling slide tube 101 engage respectively the pair of closure yokeguide posts 59 that have passed into the closure yoke assembly 46 toground the coupling slide tube 101. The firing rod 72 extends proximallyout of a proximal end of the frame 40 and through a locking hole 105 ofan anti-backup plate 106. The through hole 105 is sized to slidinglyreceive the firing rod 72 when perpendicularly aligned but to bind whentipped. A lower tab attachment 107 extends proximally from a lower lipof the proximal end of the frame 40, extending through an aperture 108on a lower edge of an anti-backup plate 106. This lower tab attachment107 draws the lower portion of the anti-backup plate 106 proximate tothe frame 40 so that the anti-backup plate 106 is perpendicular when thefiring rod 72 is distally advanced and allowed to tip top aft into abinding state when the firing rod 72 attempts to retract. An anti-backupcompression spring 110 is distally constrained by the proximal end ofthe frame 40 and distally abuts a top portion of the anti-backup plate106, biasing the anti-backup plate 106 to a locking state.

Opposing the aft bias from anti-backup compression spring 110, ananti-backup cam tube 112 slidingly encompasses the coupling slide tube101 and abuts the anti-backup plate 106. A proximally projectinganti-backup yoke 114 attached to the anti-backup cam tube 112 extendsovertop of the closure yoke assembly 46.

To cause knife retraction at the end of full firing travel, a proximalend 116 of the flexible firing rack 22 includes a tang 118 (FIGS. 4-5)that projects upwardly when the distal end 116 is advanced into a rackchannel 120 formed in the closure yoke assembly 46. This tang 118 isaligned to activate a bottom proximal cam 122 on an anti-backup releaselever 124. Alternatively or in addition, actuation of the manual releasefiring lever 34 distally moves the cam surface 99 on the hub 96 todistally move the bottom proximal cam 122 on the anti-backup releaselever 124 to effect release. Structures formed in the right and lefthalf shells 56, 58 constrain movement of the anti-backup release lever124. A pin receptacle 126 and circular pin 128, formed respectivelybetween right and left half shells 56, 58, is received through alongitudinally elongate aperture 130 formed in the anti-backup releaselever 124 distal to the bottom proximal cam 122, thus allowinglongitudinal translation as well as rotation about the circular pin 128.In the right half shell 56, a proximally open channel 132 includes aproximal horizontal portion that communicates with an upwardly anddistally angled portion that receives a rightward aft pin 134 near theproximal end of the anti-backup release lever 124, thus imparting anupward rotation as the anti-backup release lever 124 reaches the distalmost portion of its translation. A blocking structure 136, formed in theright half shell 56 proximal to the anti-backup release lever 124,prevents proximal movement thereof once assembled to maintain rightwardaft pin 134 in the proximally open channel 132.

It should be appreciated that the rack channel 120 of the closure yokeassembly 46 serves as a longitudinally aligned firing member guide thatstabilizes a distal portion of the flexible firing rack 22. Inapplications that do not include a distinct end effector closuremechanism, a longitudinally aligned firing member guide may beincorporated into the handle housing 23 as a stationary conduit.

A distal end 138 of the anti-backup release lever 124 thus is urgeddistally and downwardly, causing a rightward front pin 140 to drop intodistally open step structure 142 formed in the right half shell 56,which is urged into this engagement by a compression spring 144 hookedto a leftward hook 146 on the anti-backup release lever 124 between therightward front pin 140 and the longitudinally elongate aperture 130.The other end of the compression spring 144 is attached to a hook 148formed in the left half shell 58 in a more proximal and lower positionjust above the closure yoke assembly 46. The compression spring 144 thuspulls the distal end 138 of the anti-backup release lever 124 down andaft, which results in the rightward front pin 140 locking into thedistally open step structure 142 when distally advanced.

Once tripped, the anti-backup release lever 124 remains forward holdingthe anti-backup plate 106 perpendicularly, thus allowing the flexiblefiring rack 22 to be retracted. When the closure yoke assembly 46 issubsequently retracted when unclamping the end effector 12, an upwardlyprojecting reset tang 150 on the closure yoke assembly 46 contacts abottom distal cam 152 of the anti-backup release lever 124, lifting therightward front pin 140 out of the distally open step structure 142 sothat the anti-backup compression spring 110 can proximally push theanti-backup cam tube 112 and the anti-backup release lever 124 to theirretracted positions. To effect the distal movement of the flexiblefiring rack 22, the firing trigger 30 pivots about the firing triggerpin 74 that is connected to the housing 23. An upper portion 160 of thefiring trigger 30 moves distally about the firing trigger pin 74 as thefiring trigger 30 is depressed towards pistol grip 27, stretching aproximally placed firing trigger tension spring 162 proximally connectedbetween a spring pin 163 attached to the upper portion 160 of the firingtrigger 30 and the housing 23.

In FIGS. 2-4, the upper portion 160 (FIGS. 2-3) of the firing trigger 30engages the flexible firing rack 22 during each firing triggerdepression by a side pawl mechanism 170 that also disengages when thefiring trigger 30 is released. In particular, a ramped right-side track172 formed by a plurality of proximally and rightwardly facing beveledsurfaces 174 spaced along the flexible firing rack 22 are sequentiallyengaged by a side pawl slide assembly 176. In particular, a pawl slideblock 178 has right and left lower guides 180 that slide respectively ina left track 182 formed in a main body 183 of the closure yoke assembly46 below the rack channel 120 and a right track 184 in a closure yokerail 186 that parallels rack channel 120 and is attached to a rackchannel cover 188 that closes a rightwardly open portion of the rackchannel 120 in the main body 183 of the closure yoke assembly 46 that isdistal to the travel of the pawl slide assembly 176. A compressionspring 190 is attached between a hook 192 on a top proximal position onthe closure yoke rail 186 and a hook 193 on a distal right side of thepawl slide block 178, which keeps the pawl slide block 178 drawnproximally into contact with the upper portion 160 of the firing trigger30.

A pawl block 194 sits on the pawl slide 178 pivoting about a verticalaft pin 196 that passes through a left proximal corner of pawl block 194and pawl slide 178. A kick-out block recess 198 is formed on a distalportion of a top surface of the block 194 to receive a kick-out block200 pivotally pinned therein by a vertical pin 202 whose bottom tipextends into a pawl spring recess 204 on a top surface of the pawl slide178. A pawl spring 206 in the pawl spring recess 204 extends to theright of the vertical front pin 202 urging the pawl block 194 to rotatecounterclockwise when viewed from above into engagement with the rampedright-side track 172. A small coil spring 208 in the kick-out blockrecess 198 urges the kick-out block 200 to rotate clockwise when viewedfrom above, its proximal end urged into contact with a contoured lip 210formed in the closure yoke assembly 46 above the rack channel 120.

It should be appreciated that the stronger mechanical advantage of thepawl spring 206 over the small coil spring 208 means that the pawl block194 tends toward engagement with the kick-out block 200 rotatedclockwise. As the firing trigger 30 is fully depressed and begins to bereleased, the kick-out block 200 encounters a ridge 212 (FIG. 4) in thecontoured lip 210 as the pawl slide 178 retracts, forcing the kick-outblock 200 to rotate clockwise when viewed from above and thereby kickingout the pawl block 194 from engagement with the flexible firing rack 22.The shape of the kick-out block recess 198 stops the clockwise rotationof the kick-out block 200 to a perpendicular orientation to thecontoured lip 210 maintaining this disengagement during the fullretraction and thereby eliminating a ratcheting noise. The selection ofthe material of the flexible firing rack 22 may further dampenratcheting noise.

In FIG. 8, an alternative flexible firing rack 22 a with longitudinallyaligned rectangular top apertures 240 along a right portion of a topsurface reduces rigidity enhancing downward flexing for stowing in thepistol grip 27 of the surgical stapling and severing instrument 10 (FIG.1).

In FIG. 9, another alternative flexible firing rack 22 b includes thetop apertures 240 and in addition includes a bottom relieved portion 250rather than traverse slots 90 to enhance downward flexibility.

In FIGS. 10-17, an alternative surgical stapling and severing instrument10′ is as described above for FIGS. 1-4 with the exception ofsubstitution of a linked rack 22 c, similar to that described in theafore-referenced U.S. Pat. No. 6,905,057 instead of the flexible firingrack 22, 22 a-22 b. In addition, rather than the afore-described sidepawl mechanism 170, a chain drive 170 a fires the linked rack 22 c.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

With particular reference to FIG. 12, the linked rack 22 c includes adistal long link 300 that reciprocates within the rack channel 120 of aclosure yoke assembly 46 a, the latter differing in that the main body183 is attached to a right-side rack channel cover 188 a that includes arecess 60 a that engages the right side closure yoke guide post 59 ofthe right half shell 56. A plurality of smaller rack links 301-305proximal to the distal long link 300 have rounded adjacent ends thatallow for the links 301-305 to rotate downwardly yet present arespective portion of a toothed rack segment 88 a when in the rackchannel 120. Each link 300-305 is engaged to a looped bicycle-styledrive chain 310 by a respective pair of long pins 312 that pass throughchain link pivot holes 314 through a respective chain link 316 of thedrive chain 310. Other chain links 316 are pinned together by short linkpins 312 a.

A lower proximal idler wheel 318 rotates upon an axle 320 in an aftportion of the handle housing 23 adjacent to the closure release button36 and to the right half shell 56. A distal idler wheel 322 rotates uponan axle 324 proximal to a retracted position of the rack channel cover188 a. The drive chain 310 rotates at each looped end about these idlerwheels 318, 322. Above the lower proximal idler wheel 318, an axle 326passes within the drive chain 310 so that a retraction bias spur gear328, rotating about the axle 326, engages and forms an approximately 90degree corner in the drive chain 310. A coil spring 329 has an inner endattached to the retraction bias spur gear 328 and an outer end attachedto the right half shell 56 and is wound such that clockwise (when viewedfrom the right) firing of the drive chain 310 tightens the coil spring329, providing a retraction bias to the chain drive 170 a.

A firing trigger 30 a has an upper portion 160 a that is coupled duringeach firing depression by a firing trigger ratchet assembly 330. Inparticular, arcing gear teeth 332, which are radially equidistant fromthe firing trigger axle 74, engage a trigger spur gear 334 that freewheels on a ratchet axle 336. A disk 338 that is attached to a rightside of the trigger spur gear 334 also freely rotates on the ratchetaxle 336 and presents a ratchet pawl 340 to a ratchet gear 342 that isattached to rotate with the ratchet axle 336. A spur gear 344 is alsoattached to rotate with the ratchet axle 336 and is positioned under thechain drive 310 to engage the chain drive 310 and constrain its movementinto a dogleg shape. The ratchet gear 342 (FIG. 11) is shaped such thatthe firing trigger ratchet assembly 330 converts the clockwise rotation(CW) (when viewed from the right) of the arcing gear teeth 332 and thuscounter clockwise rotation (CCW) of the trigger spur gear 334 into a CCWrotation of the ratchet axle 336 and spur gear 344 and thus the drivechain 310. Forming the disk 338 and ratchet pawl 340 from a moldedpolymer may advantageously provide economy for a surgical stapling andsevering instrument of limited operational life as well as reducingratchet noise.

In use, the surgical stapling and severing instrument 10′ is initiallyunclamped and unfired in FIGS. 10-11. Once clamped, the firing trigger30 a is depressed a plurality of times, moving the linked rack 22 c froma retracted position (FIG. 13) to a distally fired position (FIGS.14-15) by the chain drive 170 a. In particular, the firing triggerratchet assembly 330 allows the firing trigger 30 a to distally advancethe top portion of a drive chain 310, which winds the retraction coilspring 329. The anti-backup mechanism 100 is tripped after full firingtravel by the tang 118 on the most proximal link 305 contacting theanti-backup release lever 124. The firing trigger ratchet assembly 330allows the drive chain 310 to be rotated in a retraction directionwithout coupling to the firing trigger 30 a. Alternatively, the manualretraction release lever 34 may be actuated, moving the anti-backuprelease lever 124 to a released position and backdriving gears 93, 91that retract the linked rack 22 c by engaging the tooth rack segment 88a.

In FIGS. 18A-18D, a flexible threaded cable firing mechanism 400 for anadditional alternative surgical stapling and severing instrument 10″advantageously enables a length of firing travel that would notnecessarily require a longer handle. In FIG. 18A, distal and proximalhandle grounding structures 402, 404 encompass a cylindrical firingsleeve 406 that has a central bore 408 including an inner diameter (ID)threaded portion 410 along a distal end 412 that includes an increaseddiameter distal head 414 that initially abuts the distal handlegrounding structure 402. A central portion 416 of the cylindrical firingsleeve 406 has a constant radius for reciprocally sliding a small amountthrough the distal and proximal handle ground structures 402, 404. Aproximal hub end 418 of the cylindrical firing sleeve 406 has a slightlyincreased radius that is initially spaced proximally from the proximalhandle grounding structure 404 and may be moved into abutment with thesame. A compression spring 420 encompasses the central portion 416 ofthe cylindrical firing sleeve 406, contacting a proximal surface of thedistal handle grounding structure 402 and a distal surface of an aftdirected bevel gear 422 encompassing and attached to the central portion416 of the cylindrical firing sleeve 406, providing a proximal bias tothe cylindrical firing sleeve 406.

A flexible rod 424 passes through the central bore 408 and includesouter diameter (OD) threads 426 that engage the ID threaded portion 410of the cylindrical firing sleeve 406. A cable coupling 428 is attachedat its proximal end to the flexible rod 424 and at its distal end to thefiring rod 72. An anti-rotation pin 430 extends laterally from the cablecoupling 428 to longitudinally slide along a pin guide 432 grounded tothe handle (not shown) while preventing rotation of the flexible rod424. A cable sheath 433 for reduced friction may cover a portion of theflexible rod 424 proximal to a portion that is capable of reaching theID threaded portion 410.

A left bevel gear 434 is coupled by a one-way clutch (e.g., ratchet) toa firing trigger (not shown) to turn the aft directed transverse bevelgear 422 and thus the cylindrical firing sleeve 406 in a firstdirection. Given the corresponding direction of turns of the threads410, 426, the flexible rod 424 distally translates from the cylindricalfiring sleeve 406, distally moving the cable coupling 428 and the firingrod 72. The rotation in the first direction of the cylindrical firingsleeve 406 winds a retraction coil spring 436 that encompasses and hasan inner end attached to a distal portion of the proximal hub end 418and has an outer end 437 (FIG. 18D) grounded to the handle housing (notshown). Between firing strokes when the firing trigger is uncoupled fromthe left bevel gear 434, the retraction coil spring 436 is preventedfrom turning the cylindrical firing sleeve 406 in the opposite seconddirection by a ratchet mechanism 438. In particular, a ratchet gear 440encompassing a central portion of the proximal hub end 418 is formproximally adjacent to the retraction coil spring 436. A most proximallateral surface 442 has a reduced radius. A pawl 444 is grounded to thehandle (not shown). With the cylindrical firing sleeve 406 retracted asin FIG. 18A, the pawl 444 engages the ratchet gear 440 preventingrotation in the second direction.

In FIG. 18B, as the flexible rod 424 approaches full distal travel, acable stop 446 attached to the flexible rod 424 distally advancessufficiently to contact the proximal surface of the cylindrical firingsleeve 406, translating the cylindrical firing sleeve 406 distally andcompressing the compression spring 420. The increased diameter distalhead 414 contacts a distally ramped proximal edge 448 of a rocker latch450 that pivots about pivotal connection 452 grounded to the housing(not shown). It should be appreciated that the rocker latch 450 isbiased inwardly and thus the ramped proximal catch 448 rotates tolongitudinally capture a proximal edge of the increased diameter distalhead 414 of the cylindrical firing sleeve 406. Distal translation of thecylindrical firing sleeve 406 moves the ratchet gear 440 out from underthe ratchet pawl 444 allowing the retraction coil spring 436 to rotatethe cylindrical firing sleeve 406 in the second direction, which in turnretracts the flexible rod 424. In FIG. 18C, the cable coupling 428 hasretracted sufficiently to contact a proximally ramped release arm 454 ofthe rocker latch 450, rotating the ramped proximal catch 448 out ofengagement with the increased diameter distal 414 of the cylindricalfiring sleeve 406 and allowing the compression spring 420 to urge thecylindrical firing sleeve 406 proximally, resetting the mechanism 400 tothe state of FIG. 18A.

A right bevel gear 456 may be included that is part of a manual firingrelease mechanism 458 that releases the ratchet mechanism 438 (e.g.,distally shifts cylinder firing sleeve 406, displaces ratchet pawl 444)and rotates the cylinder firing sleeve to retract the flexible rod 424.The right bevel gear 456 may include a pivot bias (not shown) thatnormally maintains the right bevel gear 456 out of contact with the aftdirected transverse bevel gear 422, whether retracted as in FIG. 18A orextended as in FIG. 18B, but which distally translates the right bevelgear 456 sufficiently for engagement when a manual firing retractionlever (not shown in FIGS. 18A-D) is actuated.

While the present invention has been illustrated by description ofseveral embodiments and while the illustrative embodiments have beendescribed in considerable detail, it is not the intention of theapplicant to restrict or in any way limit the scope of the appendedclaims to such detail. Additional advantages and modifications mayreadily appear to those skilled in the art.

For example, while the additional firing travel typical of multiplefiring strokes illustrates particular advantages of a flexible firingmember contained in the handle, it should be appreciated that aspects ofthe present invention may be applied to single firing strokeinstruments.

For another example, while a transverse cavity afforded by a pistol gripillustrates one location to retract a flexible firing member,applications consistent with the present invention may not include apistol grip. For instance, the flexible firing member may be routedaround a 180 degree bend with a retracted end closely parallel to adistal end.

For yet another example, while a manually actuated firing trigger isillustrated for clarity, remotely actuated handles may benefit from aflexible firing member incorporated into a proximal portion equivalentto a handle that is positioned and/or held by a fixture or roboticmanipulator.

1. A surgical instrument, comprising: an end effector responsive to alongitudinal firing motion to perform a surgical operation; a shaftdistally connected to the end effector; a shaft firing member slidinglyreceived by the shaft to transfer the firing motion to the end effector;and a handle proximally connected to the shaft and firing member,comprising: a flexible firing member having a distal end coupled to aproximal end of the shaft firing member, wherein the flexible firingmember comprises an articulated plurality of links, a firing actuatorreciprocally positioned by an operator to distally translate a distalportion of the flexible firing member, and a handle housing comprising abarrel portion positioned to guide the distal portion of the flexiblefiring member and comprising a stowage area communicating with thebarrel portion and positioned to guide a deflected proximal portion ofthe flexible firing member during retraction.
 2. The surgical instrumentof claim 1, wherein the flexible firing member comprises an elastomericmaterial.
 3. The surgical instrument of claim 2, wherein the flexiblefiring member further comprises a recess portion aligned for downwarddeflection.
 4. The surgical instrument of claim 2, wherein the flexiblefiring member further comprises a plurality of longitudinally alignedrecesses along a top portion for downward deflection.
 5. The surgicalinstrument of claim 1, further comprising a drive chain mechanismoperatively configured to couple the firing actuator to the flexiblefiring member.
 6. The surgical instrument of claim 1, further comprisinga manual firing release mechanism operatively configured to retract theflexible firing member.
 7. The surgical instrument of claim 1, whereinthe stowage area comprises a pistol grip.
 8. The surgical instrument ofclaim 1, wherein the handle further comprises a longitudinally alignedfiring member guide aligned with a proximal portion of the shaft firingmember, the firing actuator reciprocally positioned by an operator todistally translate a distal portion of the flexible firing member intothe longitudinally aligned firing member guide.
 9. The surgicalinstrument of claim 1, further comprising: an implement portionresponsive to longitudinal firing motion and diametrically dimensionedfor endo-surgical use, the implement portion comprising: the shaft; theshaft firing member slidingly received by the shaft to transfer thefiring motion; an elongate channel coupled to the shaft; and the endeffector responsive to the longitudinal firing motion to perform thesurgical operation, comprising an anvil pivotally coupled to theelongate channel, responsive to the closing motion from the shaft, andincluding an anvil channel, a firing bar attached to the firing memberand including a distally presented cutting edge longitudinally receivedbetween the elongate channel and the anvil, and a staple device receivedin the elongate channel and responsively coupled to the firing bar toform staples against the anvil.
 10. The surgical instrument of claim 9,wherein the shaft further comprises a closure sleeve attached to pivotthe anvil, the handle further comprises a closure trigger, and thelongitudinally aligned firing member guide comprises a closure yokedistally positioned by the closure trigger to translate the closuresleeve.
 11. A surgical instrument, comprising: an end effectorresponsive to a longitudinal firing motion to perform a surgicaloperation; a shaft distally connected to the end effector; a shaftfiring member slidingly received by the shaft to transfer the firingmotion to the end effector; and a handle proximally connected to theshaft and firing member, comprising: a flexible firing member having adistal end coupled to a proximal end of the shaft firing member, afiring actuator reciprocally positioned by an operator to distallytranslate a distal portion of the flexible firing member, and a handlehousing comprising a barrel portion positioned to guide the distalportion of the flexible firing member and comprising a stowage areacommunicating with the barrel portion and positioned to guide adeflected proximal portion of the flexible firing member duringretraction, wherein the flexible firing member comprises an elastomericmaterial, a recess portion aligned for downward deflection, and whereinthe recess portion in turn comprises a plurality of transverse slotspassing perpendicularly to a longitudinal axis of and passing through alower portion of the flexible firing member.
 12. A surgical instrument,comprising: an end effector responsive to a longitudinal firing motionto perform a surgical operation; a shaft distally connected to the endeffector; a shaft firing member slidingly received by the shaft totransfer the firing motion to the end effector; and a handle proximallyconnected to the shaft and firing member, comprising: a flexible firingmember having a distal end coupled to a proximal end of the shaft firingmember, wherein the flexible firing member further comprises a toothedgear rack segment, a firing actuator reciprocally positioned by anoperator to distally translate a distal portion of the flexible firingmember, and a handle housing comprising a barrel portion positioned toguide the distal portion of the flexible firing member and comprising astowage area communicating with the barrel portion and positioned toguide a deflected proximal portion of the flexible firing member duringretraction.
 13. A surgical instrument, comprising: an end effectorresponsive to a longitudinal firing motion to perform a surgicaloperation; a shaft distally connected to the end effector; a shaftfiring member slidingly received by the shaft to transfer the firingmotion to the end effector; and a handle proximally connected to theshaft and firing member, comprising: a flexible firing member having adistal end coupled to a proximal end of the shaft firing member a firingactuator reciprocally positioned by an operator to distally translate adistal portion of the flexible firing member, and a handle housingcomprising a barrel portion positioned to guide the distal portion ofthe flexible firing member and comprising a stowage area communicatingwith the barrel portion and positioned to guide a deflected proximalportion of the flexible firing member during retraction; wherein theflexible firing member further comprises a longitudinally alignedplurality of ramped recesses, the handle further comprising a pawlmechanism positioned by the firing actuator to engage a selected one ofthe plurality of ramped recesses and thereby distally transfer theflexible firing member.
 14. A surgical instrument, comprising: an endeffector responsive to a longitudinal firing motion to perform asurgical operations a shaft distally connected to the end effector; ashaft firing member slidingly received by the shaft to transfer thefiring motion to the end effector; and a handle proximally connected tothe shaft and firing member, comprising: a flexible firing member havinga distal end coupled to a proximal end of the shaft firing member, afiring actuator reciprocally positioned by an operator to distallytranslate a distal portion of the flexible firing member, and a handlehousing comprising a barrel portion positioned to guide the distalportion of the flexible firing member and comprising a stowage areacommunicating with the barrel portion and positioned to guide adeflected proximal portion of the flexible firing member duringretraction; wherein the flexible firing member further comprises aspring attachment, the handle further comprising a retraction springattached to the handle housing in the stowage area and attached to thespring attachment on the firing member to bias the flexible firingmember into the stowage area.
 15. A surgical instrument, comprising: anend effector responsive to a longitudinal firing motion to perform asurgical operation; a shaft distally connected to the end effector; ashaft firing member slidingly received by the shaft to transfer thefiring motion to the end effector; and a handle proximally connected tothe shaft and firing member, comprising: a flexible firing member havinga distal end coupled to a proximal end of the shaft firing member, afiring actuator reciprocally positioned by an operator to distallytranslate a distal portion of the flexible firing member, a handlehousing comprising a barrel portion positioned to guide the distalportion of the flexible firing member and comprising a stowage areacommunicating with the barrel portion and positioned to guide adeflected proximal portion of the flexible firing member duringretraction; and a drive chain mechanism operatively configured to couplethe firing actuator to the flexible firing member; wherein the flexiblefiring member comprises an articulated plurality of links attached tothe drive chain mechanism.
 16. The surgical instrument of claim 15,wherein the drive chain mechanism further comprises a one-way clutchengagement between the firing actuator and the articulated plurality oflinks for multiple firing strokes.
 17. A surgical instrument, furthercomprising: an end effector responsive to a longitudinal firing motionto perform a surgical operation; a shaft distally connected to the endeffector; a shaft firing member slidingly received by the shaft totransfer the firing motion to the end effector; and a handle proximallyconnected to the shaft and firing member, comprising: a flexible firingmember having a distal end coupled to a proximal end of the shaft firingmember, a firing actuator reciprocally positioned by an operator todistally translate a distal portion of the flexible firing member, ahandle housing comprising a barrel portion positioned to guide thedistal portion of the flexible firing member and comprising a stowagearea communicating with the barrel portion and positioned to guide adeflected proximal portion of the flexible firing member duringretraction; a drive chain mechanism operatively configured to couple thefiring actuator to the flexible firing member; and a retraction coilspring engaged between the handle housing and the drive chain mechanismfor a retraction bias to the flexible firing member.
 18. A surgicalinstrument, comprising: an end effector responsive to a longitudinalfiring motion to perform a surgical operation; a shaft distallyconnected to the end effector; a shaft firing member slidingly receivedby the shaft to transfer the firing motion to the end effector; and ahandle proximally connected to the shaft and firing member, comprising:a flexible firing member having a distal end coupled to a proximal endof the shaft firing member, a firing actuator reciprocally positioned byan operator to distally translate a distal portion of the flexiblefiring member, a handle housing comprising a barrel portion positionedto guide the distal portion of the flexible firing member and comprisinga stowage area communicating with the barrel portion and positioned toguide a deflected proximal portion of the flexible firing member duringretraction; a drive chain mechanism operatively configured to couple thefiring actuator to the flexible firing member; a longitudinal firingmember guide comprising a cylindrical firing sleeve received forlongitudinal rotation within the handle housing and including an innerdiameter threaded longitudinal central bore, the flexible firing membercomprising an outer diameter threaded flexible rod received in thecentral bore, an anti-rotation guide coupled between the handle housingand the flexible rod, and a firing transmission operatively configuredto convert reciprocal motion of the firing actuator into a rotation ofthe cylindrical firing sleeve to effect distal translation of theflexible rod.
 19. The surgical instrument of claim 18, furthercomprising a retraction mechanism operatively configured to store acounter rotation force during firing of the flexible rod.
 20. A surgicalinstrument, comprising: an implement portion responsive to a firingmotion and diametrically dimensioned for endo-surgical use, theimplement portion comprising: a shaft; a shaft firing member slidinglyreceived by the shaft to transfer a firing motion; an elongate channelcoupled to the shaft; an anvil pivotally coupled to the elongatechannel, responsive to the closing motion from the shaft, and includingan anvil channel; a firing bar attached to the firing member andincluding a distally presented cutting edge longitudinally receivedbetween the elongate channel and the anvil; and a staple device receivedin the elongate channel and responsively coupled to the firing bar toform staples against the anvil; and a handle proximally connected to theshaft and firing member, comprising: a longitudinal firing member guidealigned with a proximal portion of the shaft firing member; a flexiblefiring member having a distal end coupled to a proximal end of the shaftfiring member; a firing actuator reciprocally positioned by an operatorto distally translate a distal portion of the flexible firing memberinto the longitudinal firing member guide; and a handle housingcomprising a stowage area communicating with a proximal end of thelongitudinal firing member guide to receive a deflected proximal portionof the flexible firing member during retraction; wherein thelongitudinal firing member guide comprises a cylindrical firing sleevereceived for longitudinal rotation within the handle housing andincluding an inner diameter threaded longitudinal central bore, theflexible firing member comprising an outer diameter threaded flexiblerod received in the central bore, an anti-rotation guide coupled betweenthe handle housing and the flexible rod, and a firing transmissionoperatively configured to convert reciprocal motion of the firingactuator into a rotation of the cylindrical firing sleeve to effectdistal translation of the flexible rod.